Truncated Taxpayer Identification Numbers (REG-148873-09)

After more than 50 years as a widely available non-secret identifier it is not practical to repurpose the SSN as a secret password, and the IRS should not feel obligated to assist organization who wish to use the SSN as a password equivalent. Rather it should be cooperating with whatever organizations are building effective identity procedures. An SSN can never be really secret - there is no sense in halfway measure to make it slightly obscure.